This invention relates to filter assembly with particular utility in the filtration of viscous polymer melts in which high shear forces are encountered.
A thermoplastic polymer is very often formed into a finished or semi-finished state by an extrusion process in which a polymer, and optionally other ingredients to be incorporated therein, is subjected to a compounding operation before being extruded through an orifice of suitable dimensions into a mold or into the air in the form of a sheet or strand.
Where it is required that the polymer be of a particularly high quality it is usually necessary to pass the extruded melt through a filter to remove gel particles, solid impurities from the polymer itself or the additives compounded therewith and burnt stock where local overheating may have led to partial decomposition of the polymer.